PROJECT SUMMARY (Macromolecular Crystallography Laboratory) The three-dimensional structure determination of macromolecules such as proteins and nucleic acids using X- ray crystallography provides unique insights into the function of the molecule or molecular complex. The OU- Norman Macromolecular Crystallography Laboratory Core (MCL) provides expertise and state-of-the-art instrumentation to support the Oklahoma COBRE in Structure Biology (OCSB) affiliated research groups and other research groups involved in structural biology research, particularly in protein crystallography, across the State of Oklahoma. The MCL accomplishes this by utilizing robotic instrumentation for the screening of crystallization conditions, the utilization of a high flux micro focus X-ray generator and a state-of-the-art hybrid pixel X-ray detector for data collection along with up to date maintenance of computational resources to process and determine the structure of the macromolecules of interest. The MCL director, Dr. Leonard Thomas, is a full time Ph.D. crystallographer. The facility also employs a Graduate Assistant to aid in the screening of crystallization conditions and the preparation of samples for collection of X-ray data. The MCL provides training to students, postdoctoral fellows and faculty who are interested in macromolecular structure determination. During the OCSB Phase I funding the MCL user base has been greatly expanded and the facility will continue to expand its user base by providing expertise, state-of-the-art facilities and training during the OCSB Phase II.